Knowing that, they should have monitored him until he was gone.

I have similar cameras monitoring my other 10 units.

I'm going to monitor the activity of her unit for this month, till her lease expires.  

I already use Google Drive/ Work.Any suggestions for tablets, monitors etc?

Monitoring the work of a property management company would take time and energy too.

You can set up more appropriate gathering spaces through landscape/design/providing lawn chairs/etc.But, really, it is very difficult to monitor and enforce guest policy, so learn to deal with it.  

Monitor market rents and vacancy rates then react accordingly. 

.- Always interface between the tenant and the repair person to monitor work being done.

Even so, I would create an addendum to the lease that indicates that the tenant is responsible for maintaining the equipment, paying the monitoring fee and uninstalling it when they vacate.

And create letters and forms and mail them out....on and on.And there will be meetings on how to manage all of the above, and who will be supervising the person(s) who handle the calls and the paperwork and the people who come in person....Honestly, having a city inspector would be easier to manage, than having who knows how many independent inspectors who will also probably have to be credentialed in some way, which would have to be monitored and filed.And how do they handle disputes?